Halsted: Mvcological Notes 77 



" ^ 



sweet corn were grown, only one of w^hich has shown unmistakable 



signs of the bacterial disease {Pscndouiouas Stcivarti E. F. Smith), 



namely, '' First of all.*' This is a very small form, the chief merit 



of which is its earliness. A second crop grown with the stubble of 



the first had some of the plants decay away at the base, due to the 

 bacteriosis. 



Smut {^Ustilago maydis DC.) w^as quite abundant upon the 

 same variety, and like the Pscndouioias was rarely met with else- 

 where in the plot where four other varieties of sweet corn were 

 grown. 



Rotation of Crops a valuable Fungicide. — The fairly well knowii 

 fact stated in the headline was brought strikingly to the attention 

 of the writer in an experiment with egg-plants. One plot had been 

 in this crop for three successive years, and a half of it w^as again 

 set to egg-plants for 1898. A duplicate set of plants was placed 

 upon a half plot of land where that crop probably had never been 

 grown. The treatment as to culture and kinds and times of spray- 

 ing were the same upon the two areas, and the results are shown 



in the following table : 



New Ground. 



Marketable. 



Sound fruits. 



130 



Decayed fruits. 



21 



Old Ground. 





Sound fruits. 



27 



Decayed fruits. 



21 



Small. Total 



80 210 



19 40 



15 42 



45 66 



There were five times as many sound fruits upon the new as 

 upon the old land, w^hilc the decayed ones were only 16 per cent, 

 upon the new land and 61 per cent, upon the old land. The point 

 of special interest in this connection was that nine sprayings were 

 made with Bordeaux upon one row^ of each of the half plots and 

 this mixture was not able to keep the plants in the old land in 

 good health. In short, a crop may be continued so long upon the 

 same land that a fungicide may fail to do its effective work, when 

 a resort to some other crop is the only practical method of deahng 

 with the troubles. 



.Sulphur as a Remedy for Potato Diseases, — Sulphur was added 

 to five of the twenty-four belts of land in one portion of the Ex- 

 periment Area devoted to tests for a remedy for the Potato Scab 

 {fjospora scabies Thax.). 



